The 5th conference in the successful ASM series on Beneficial Microbes communicates the latest research on the microorganisms that underpin the health and fitness of animals, including humans, plants and other hosts. The conference brings together researchers from multiple scientific disciplines, to catalyze new synthesis and shape future research. Conference themes include host-microbe and among-microbe interactions in associations of different complexity, the directionality of interactions (“from correlation to causation”), immune system function from functional and evolutionary perspectives, spatiotemporal dynamics of microbial populations, and routes for translation to therapeutic benefits in medicine and veterinary science. As well as internationally-renowned invited speakers, most talks are selected from submitted abstracts. The Organizing Committee particularly encourages the participation of postdocs and students.